Stormwater options discussed

Times Reporter     

 

At the May 21 town council meeting David Seeliger and Colin McNab from MPE Engineering brought forward details and suggestions for stormwater management. 

The Engineering Assessment of Preferred Stormwater Management Options report was created for municipalities involved in the Co-operative Stormwater Management Initiatives (CSMI). 

CSMI was formed to assist municipalities and the Western Irrigation District (WID) in finding solutions to the stormwater issues that affect each sector and municipality in different ways. 

There are numerous possible strategies or options that were drawn from the analysis that have the potential to reduce the nutrient loading from the stormwater runoff, but only a few can be effectively implemented.

“So looking at the existing water quality in the canals, the existing canals are close to exceeding water quality limits by the WID stormwater guidelines that were developed a number of years ago,” said Seeliger. 

“Therefore to let stormwater into the canals like may have been done more traditionally, if we do permit that as an alternative, we really need to improve stormwater to a high level to not to continue to degrade the water quality.”

The preferred stormwater management solution is an out-of-canal alternative, where all urban stormwater is diverted away from the irrigation system, treated as necessary, and eventually released into a natural water course. By going with this method there is reduced risk to the overall irrigation infrastructure. 

Stormwater runoff generated by rare events, such as the one-in-100-years flood situations, should be allowed to go into the irrigation system, providing an emergency escape route for the runoff. A strict irrigation nutrient-loading guideline would not need to be followed with the out-of-canal option. Strathmore west and north study areas should also be considered for diversion, said Seeliger, which would allow the stormwater to flow directly into Serviceberry Creek, and not impact the already poor water quality within the B canal. 

The recommendations include proceeding with the initial implementation planning phase, which involves making key decision, confirming next steps, conceptual design and stormwater guidelines. It also involves having future land development incorporate low impact development practices, stormwater reuse to reduce overall volume, and ponds or wetlands for management of peak flows to meet the CSMI guidelines. 

IN the 2014 irrigation season it is proposed that enhanced water quality monitoring be implemented, continued and further refined through evaluation of locations, and timing samples on a more frequent basis. Discussion with the regulators should also take place, to familiarize them with the initiative and to review the regulatory framework. 

Council made and approved a motion supporting the findings and recommendations, and authorized the town to participate in the next step so of the Co-operative Stormwater Management Initiative Implementation Planning Phase.